5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
commit c6adf659a8ba85913e16a571d5a9bcd17d3d1234 upstream
Add missing check to block non-AF_CAN binds.
Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:
bind$xdp(r2, &(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.
Link: https://syzkaller.appspot.com/text?tag=CrashLog&x=11ff9d8c480000
Reported-by: syzbot+5aed6c3aaba661f5b917@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@xxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/can/isotp.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1129,6 +1129,9 @@ static int isotp_bind(struct socket *soc
if (len < ISOTP_MIN_NAMELEN)
return -EINVAL;
+ if (addr->can_family != AF_CAN)
+ return -EINVAL;
+
/* sanitize tx/rx CAN identifiers */
tx_id = addr->can_addr.tp.tx_id;
if (tx_id & CAN_EFF_FLAG)
